Those suffering from knee pain due to osteoarthritis shouldnt put their hopes in Vitamin D as the answer to their aching joints, according to a new study. Once touted as a super nutrient, previous research suggested that high levels of vitamin D in the blood of those with the joint disorder benefited from a slower progression of symptoms. Now, this latest research overturns the theory. Published in the Journal of the American Medical Association, the study gave a high amount of vitamin D to the treatment group, at least 2,000 international units (IU) per day, which is far higher than the recommended daily amount of 600 to 800 IU. A review included 146 patients with knee osteoarthritis who took a daily dose of vitamin D or a vitamin-free placebo for two years.